What does the process consist of?

It’s a prolonged fermentation of the coffee, within the cell structure of the fruits. The chemical reaction of fermentation takes place when water mixes with the natural sugars present in the fruit. Yeast, bacteria and other naturally present microorganisms decompose the sugars and transform these into acids or alcohol.

How do you reach fermentation?

The entire fruits that envelop the coffee must be placed in a hermetically closed space, usually a stainless steel tank, although plastic tanks or even bags do the job just as well, as long as the oxygen can be eliminated and the container (or bags) can be filled with CO2. While the coffee is fermenting, bacteria decompose the sugar to turn it into CO2 and alcohol.

Once sufficient CO2 has been generated, the pressure within the hermetically closed space will increase. Therefore, a valve needs to be installed, to decrease the pressure without letting oxygen enter the tank or space. The duration of this fermentation process can last anywhere between a couple of hours to a few days. THE CO2 prolongs the fermentation process because it slows down the decomposition of the sugars, which allows for unusual flavors to develop inside the coffee grains, without the vinegar-like flavors of classic fermentation processes.

The PH also evolves more slowly, which means there will be less acidity from the alcohol. The temperature as well as the time of fermentation play key roles. Of course, with the right practice and experience, you can master and control these variables to optimize results.

The process can be used for washed and natural coffees

Carbonic maceration is not a new way to process coffee, but one that can be added to the process of washed or natural coffees. In a washed carbonic maceration process, the ripened fruits are picked by hand, then classified and depulped, before being put into closed tanks (or bags). In a natural carbonic maceration process, the fruits are placed in the closed tanks and, after being processed, they are dried on African beds until an ideal level of humidity is reached.

Which additional qualities do you obtain with carbonic maceration?

The slow and controlled fermentation process helps to develop and enrich the grains’ flavors, and this technique is still developing to reach its full potential, seeking the best ways to reach optimum aromatic enrichment. However, the technique is already well developed and leads to sweeter flavors and more body in the cup.